I just read "Collapse" by Jared Diamond.  It's about societies that have collapsed and some that haven't and why, etc.

It does offer some hopeful examples for the future of the planet.  One thing I've seen erroneously stated by you and others is the population explosion.  Most population statisticians see the world population levelling and declining in the future, unless of course, something causes it to explode again.  I looked at the zero population group's growth statistics a while ago and even they show a levelling of population in the future. 

http://en.wikipedia.org/wiki/World_population

"The UN estimated in 2000 that the world's population was then growing at the rate of 1.4 percent (or 91 million people) per year. This represents a decrease in the growth rate from its level in 1990, mostly due to decreasing birth rates.

The first five years of the 21st century saw something of a decline in the overall population growth, with the world's population increasing at a rate of about 76 million people per year as of 2005.

The future growth of population is difficult to predict. Birth rates are declining slightly on average, but vary greatly between developed countries (where birth rates are often at or below replacement levels) and developing countries. Death rates can change unexpectedly due to disease, wars and catastrophes, or advances in medicine. The UN itself has issued multiple projections of future world population, based on different assumptions. Over the last 10 years, the UN has consistently revised these projections downward."

World population growth 'falling'

http://news.bbc.co.uk/2/hi/americas/3560433.stml

So if you're worried about "too many people" (I don't think God is), there's hope that the increase is levelling.

I highly recommend seeing the PBS interview with Sir John Houghton.